Abstract:
Researchers have used the world's thinnest material to create a new type of technology, which could be used to make super-fast electronic components and speed up the development of drugs.

Manchester physicists pioneer new super-thin technology

Manchester, UK | Posted on February 28th, 2007

Physicists at The University of Manchester and The Max-Planck Institute in Germany have created a new kind of a membrane that is only one atom thick.

It's believed this super-small structure can be used to sieve gases, make ultra-fast electronic switches and image individual molecules with unprecedented accuracy.

The findings of the research team is published today (Thursday 1 March 2007) in the journal Nature.

Two years ago, scientists discovered a new class of materials that can be viewed as individual atomic planes pulled out of bulk crystals.

These one-atom-thick materials and in particular graphene - a gauze of carbon atoms resembling chicken wire - have rapidly become one of the hottest topics in physics.

However, it has remained doubtful whether such materials can exist in the free state, without being placed on top of other materials.

Now an international research team, led by Dr Jannik Meyer of The Max-Planck Institute in Germany and Professor Andre Geim of The University of Manchester has managed to make free-hanging graphene.

The team used a combination of microfabrication techniques used, for example, in the manufacturing of microprocessors.

A metallic scaffold was placed on top of a sheet of graphene, which was placed on a silicon chip. The chip was then dissolved in acids, leaving the graphene hanging freely in air or a vacuum from the scaffold.

The resulting membranes are the thinnest material possible and maintain a remarkably high quality.

Professor Geim - who works in the School of Physics and Astronomy at The University of Manchester - and his fellow researchers have also found the reason for the stability of such atomically-thin materials, which were previously presumed to be impossible.

They report that graphene is not perfectly flat but instead gently crumpled out of plane, which helps stabilise otherwise intrinsically unstable ultra-thin matter.

Professor Geim and his colleagues believe that the membranes they have created can be used like sieves, to filter light gases through the atomic mesh of the chicken wire structure, or to make miniature electro-mechanical switches.

It's also thought it may be possible to use them as a non-obscuring support for electron microscopy to study individual molecules.

This has significant implications for the development of medical drugs, as it will potentially allow the rapid analysis of the atomic structures of bio-active complex molecules.

"This is a completely new type of technology - even nanotechnology is not the right word to describe these new membranes," said Professor Geim.

"We have made proof-of-concept devices and believe the technology transfer to other areas should be straightforward. However, the real challenge is to make such membranes cheap and readily available for large-scale applications."

In addition to Meyer and Geim, researchers involved in this work include Kostya Novoselov and Tim Booth from The University of Manchester, Mikhail Katsnelson from The University of Nijmegen in the Netherlands, and Sigmar Roth of The Max Plank Institute in Germany.

The research of Professor Geim, Dr Kostya Novoselov and colleagues at the University of Manchester led to the discovery of a new class of materials called two-dimensional atomic crystals back in 2004. Professor Geim was recently awarded the 2007 Mott Medal and Prize by The Institute of Physics for his discovery of graphene and his 'remarkable contribution' to science.

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About University of ManchesterBy 2015 The University of Manchester aims to be among the top 25 universities in the world, at the highest international level of research excellence.

The University already has a global reputation for being at the forefront of innovative and enterprising research. With research funding in the region of £170 million rising per year, and Research Assessment Exercise (RAE) results that rival those of Oxford and Cambridge, The University of Manchester is on course to meet its target by 2015.

In the 2001 RAE the separate institutions UMIST and the Victoria University Manchester together accrued a total of 46 top grades of 5* and 5 for its research activity, while Oxford accrued 42 and Cambridge 48.

Prof Geim is available for interview, but only via email or telephone from Wednesday 28 February 2007 onwards.

Photographs of Professor Geim are available, along with an image of atomic gauze hanging on a scaffold of golden wires and an artist's impression of the chicken wire of carbon atoms.

The full title of the paper published in Nature is 'The structure of suspended graphene sheets'. Copies are available on request.

Research collaborators: The Max Planck Institute for Solid State Research, Stuttgart, Germany, The Manchester Centre for Mesoscience and Nanotechnology, The University of Manchester, The Institute for Molecules and Materials, The Radboud University of Nijmegen, The Netherlands.